Traveller's diarrhea: which vaccines?

Diarrheal diseases are a major cause of child morbidity and mortality, particularly in developing countries. It is estimated that diarrheal diseases and typhoid fever cause around 2.5 million deaths per year in the world. Four bacteria and one virus share this responsibility: Shigella spp, Escherichia coli ETEC, Vibrio cholerae, Salmonella typhi and rotavirus. People travelling in countries with high endemicity of diarrhoeal diseases risk facing these four bacteria or the less common rotavirus, which is usually active in infants, even though some cases of diarrhoea due to rotavirus have already been reported in adults. The usual recommendations concerning basic measures of hygiene are most of the time quickly forgotten and followed only by a small number of travellers (12). Therefore, apart these useful recommendations, it is therefore necessary to consider complementary actions for controlling these diseases which are mainly transmitted by contaminated water and food. This article aims at giving an overview of currently available and future vaccines for preventing travellers' diarrheas.     

Cutaneous lymphomas: which pathological classification?

Cutaneous lymphomas are rare and although some are a manifestation of systemic lymphoma, the majority arise primarily from the skin. These primary cutaneous lymphomas comprise predominantly T cell subtypes and represent a wide spectrum of disorders. Pathologists can currently choose to label these conditions according to three classifications (REAL, EORTC or WHO) but each has shortcomings. Nonetheless, in an attempt to unify the field, we would recommend that pathologists make every attempt to categorise these conditions according to the WHO classification. This classification can encompass all the conditions and aligns the cutaneous lymphomas with the broader systemic lymphoproliferative conditions.     

Hyperamylasemia after cardiac surgery: which significance?

We report the case of an 82-year-old woman, suffering of aortic valve stenosis, hospitalized for an aortic valve replacement surgery. This woman presented a hyperamylasemia during the early postoperative period. This raised the question of issue and explanation of this hyperamylasemia. A review of the literature showed that hyperamylasemia was reported in a large number of patients undergoing cardiac surgery, with various serum amylase levels and time courses. Mechanisms of this hyperamylasemia remain poorly understood and the interest of amylasemia measurement after cardiothoracic surgery is not clearly defined. Since postoperative hyperamylasemia can result from a tissular hypoxia, blood lactate measurement could be a more effective biochemical marker.     

Schistocytes: which definition should be taken and which method should be used to identify and count them?

Schistocytes result from red cell fragmentation. The identification of the schistocytes is critical for appropriate management of the patients. We report the results of a survey about the determination of schistocytes. The analysis of the answers of 24 well-trained biologists points out the different approaches used to count these cells, and the urgent need for guidelines to identify and enumerate them.     

Weight correction of MoM values: which method?

BACKGROUND: Adjusting maternal serum markers for maternal weight is considered to be a standard practice when screening for pregnancies associated with Down's syndrome. The choice of model for taking maternal weight into account is, however, rarely explicitly evaluated. METHOD: The relationship between the maternal serum markers alphafetoprotein (AFP), human chorionic gonadotropin (HCG) and unconjugated oestriol (uE3), determined with the Beckman Coulter access reagents and maternal weight was investigated in a cohort of 752 Belgian women being screened for pregnancy associated with Down's syndrome. Two different models (the log-linear equation and the linear-reciprocal equation) were used to determine the relationship between the serum markers and maternal weight. RESULTS: A significant relationship between log(10) multiples of median (MoM) values and weight (kg) was obtained for all markers, and the log-linear model had higher coefficients of determination (r(2)) when compared with the linear-reciprocal model. Weight correction with either method achieved the optimum effect that the correction factor for a woman with a population median weight of 65.5 kg was not significantly different from 1. Simulated weight-corrected MoM values with the two approaches were compared and variation was estimated. The mean difference between the weight-corrected MoM values calculated by the two methods was 7.8% (SD 4.3%) for AFP, 14.0% (4.4%) for HCG and 5.9% (3.2%) for uE3. This resulted in a difference in risk estimate of 1.66-5.34% for Down's syndrome owing to weight correction algorithm differences in women of median weight. CONCLUSION: The log-linear weight correction approach was shown to be marginally more effective by a goodness-of-fit analysis. Differences in weight-corrected MoM values estimated with the two approaches are highly significant (p<0.0001, Wilcoxon's paired sample test), but the effect on risk calculation was not significant. It was observed that the changes in risk became significant the more the MoM correction factors deviated from 1.     

GABAAreceptor subtypes: which,where and why?

Synaptic inhibition in the vertebrate central nervous system is mediated predominantly by subtypes of the GABA_Areceptor, which comprise different pentameric combinations of the products of 13 genes. In this article, we review the results of recent experiments that are helping to define binding-site determinants, on GABA_Areceptors, for various ligands and some clinically-important modulators. New and sometimes conflicting data, on the polypeptide compositions of native subtypes, will also be discussed. Studies such as those described here should ultimately lead to a molecular understanding of receptor–ligand interactions, and the biological basis for the large number of subtypes that appear to exist in brain.     

Canine parvovirus infection: which diagnostic test for virus?

Five laboratory tests for diagnosis of canine parvovirus type 2 (CPV-2) infection were employed to test 89 faecal samples collected from dogs with diarrhoea. The tests analysed were immunochromatography (IC), haemagglutination (HA), virus isolation (VI), conventional and real-time PCR. IC, HA, VI and conventional or real-time PCR were able, respectively, to detect CPV-2 antigen or nucleic acid in 41, 50, 54, 68 and 73 of the samples. The best correlation was found between conventional and real-time PCR, with an overall agreement of 94.38%. Sixty-eight samples that tested positive by HA, VI or conventional PCR were subjected to antigenic and/or genetic analyses of the CPV-2 strains by monoclonal antibody (MAb), restriction fragment-length polymorphism (RFLP) and/or sequence analyses. In sum, out of the 68 strains analysed, 26 were characterised as CPV-2a, 18 as CPV-2b and 24 as a CPV-2 Glu-426 mutant recently identified in Italy.     

The diagnosis of pertussis: which method to choose?

Despite the introduction of routine vaccination against pertussis for more than a half century, leading to a drastic decline in the number of reported cases, pertussis continues to be an important respiratory disease afflicting unvaccinated infants and previously vaccinated children as well as adults in whom immunity has waned. The diagnosis of pertussis is challenging and accurate laboratory identification of Bordetella infections remains problematic. Common laboratory diagnostic methods used for pertussis diagnosis include culture, direct-fluorescent-antibody testing (DFA), serology and polymerase chain reaction (PCR). Culture of Bordetella pertussis is highly specific but fastidious and has limited sensitivity. DFA provides a much more rapid result, but has the disadvantage of poor sensitivity and specificity. Serology is not useful in infants. In older persons, it is hampered by the limitations of paired sera and it provides mainly a retrospective diagnosis. Such limitations of conventional diagnosis testing have led to the development of PCR assays. Notwithstanding its lack of standardization, PCR has been found to be more sensitive and more specific than other methods. In this report, we aimed to review current knowledge about the available diagnostic methods and tests that accurately diagnose pertussis.     

Ventricular assist device selection: which one and when?

Advances in mechanical circulatory support have significantly expanded the treatment options for patients with heart failure, whether acute or chronic. There are numerous devices available that offer patients short-, intermediate-, and long-term duration of support depending on their clinical needs and cardiac recovery. Each device has its own technical considerations and the decision which device to use depends on several factors, including what is available, the degree of support required, and expected duration of support. Additional issues that need to be considered in choosing level of support include right heart function, respiratory failure, and multi-organ derangements. A widespread availability of short-term ventricular assist devices and timely institution for effective hemodynamic support will translate into improved patient outcomes whether that is successful transfer to a tertiary care facility or recovery of inherent cardiac function. Implantable ventricular assist devices have and will continue to evolve into smaller and more durable devices, and the future for patients with advanced heart failure looks ever-more promising.The limited efficacy of medical therapy to treat end-stage heart failure (ESHF), shortage of available donor hearts, and the increasing number of patients who do not qualify for transplant candidacy despite worsening heart failure have all fueled the evolution of mechanical circulatory support. Currently, long-term implantable left ventricular assist devices (LVAD) have significantly expanded treatment options for patients with ESHF as a bridge-to-decision, recovery, transplant, or destination therapy (DT) (1). Mirroring the progress and success of long-term LVADs, advances have similarly been made in the use of short-term VADs for the treatment of cardiogenic shock, whether in the cardiac catheterization laboratory or the post-cardiotomy setting (2). However, despite improving technology, there is still a growing need for wider application of these short-term devices, especially in non-tertiary care centers where lack of access to this technology results in delayed referral and transport to advanced centers and potentially compromises patient outcome. In this setting, there is still a question as to the ideal support device, duration of support, and timing to bridge these critical patients to a longer-term device. Device selection in these circumstances depends on several factors, including the degree of support that is required acutely, logistical/technical considerations, concomitant issues besides left ventricular dysfunction (especially right ventricular or pulmonary dysfunction), and what is available. We review current devices approved by the Food and Drug Administration for short-, intermediate-, and longer-term support, as well as examine the critical issues to be considered with selecting a device. These include timing of support, varying technical specifics of each device, and expected duration of support. In addition, we provide the advantages and disadvantages of each device and provide an algorithm for decision-making and device selection in these patients.     

Neural differentiation from embryonic stem cells: which way?

Embryonic stem (ES) cells can in theory produce all cell types of a living organism while renewing themselves with a stable genetic background. These unique features make ES cells a favorable tool for biomedical researches as well as a potential source for therapeutic application. A first step for approaching to ES cells is the directed differentiation to cells of interest, such as the neural cell lineage. Here, we summarize the up and down sides of each category of neural differentiation protocols that have so far been used in mouse and human ES cells, and introduce an efficient and plausible method used in our laboratory for derivation of neuroectodermal cells from human ES cells. This synthesis has led to our suggestions on issues for future design of neural differentiation protocols.     

Teenage pregnancy and congenital anomalies: which system is vulnerable?

BACKGROUND: Teenage pregnancy may be associated with some forms of congenital anomalies. The objective of this study was to identify the types of congenital anomalies associated with teenage pregnancy. METHODS: We carried out a retrospective cohort study of 5 542 861 nulliparous pregnant women younger than 35 years of age with a live singleton birth between 1995 and 2000 in the USA. RESULTS: Compared with adult pregnancy (20-34 years old), and after adjustment for confounding variables, teenage pregnancy (13-19 years old) was associated with increased risk of central nervous system anomalies [odds ratio (OR) 1.08; 95% confidence interval (CI): 1.01, 1.16], gastrointestinal anomalies (OR: 1.39; 95% CI: 1.31, 1.49) and musculoskeletal/integumental anomalies (OR: 1.06; 95% CI: 1.03, 1.10). The teenage pregnancy associated increase in risk for central nervous system anomalies was mainly attributable to anomalies other than anencephalus, spina bifida/meningocele and hydrocephalus and microcephalus; for gastrointestinal anomalies the risk was mainly attributable to omphalocele/gastroschisis; and for musculoskeletal/integumental anomalies the risk was mainly attributable to cleft lip/palate and polydactyly/syndactyly/adactyly. No increased risk was found for circulatory/respiratory anomalies, urogenital anomalies, or Down's syndrome. CONCLUSIONS: Teenage pregnancy increases the risks of congenital anomalies in central nervous, gastrointestinal and musculoskeletal/integumental systems.     

How do we determine which drug-induced neuroplastic changes are important?

Although many drug-induced neural changes are known, progress has been slow in identifying the ones that actually mediate addiction. Identifying changes that are specific to particular elements of the transition from initial to habitual to relapsing drug use may be a fruitful strategy for pinpointing which forms of drug-induced plasticity are critical for addiction.